diff --git a/src/gui_gtk_f.h b/src/gui_gtk_f.h
index 73b0024..fa0f40a 100644
--- a/src/gui_gtk_f.h
+++ b/src/gui_gtk_f.h
@@ -9,8 +9,12 @@
 #ifndef __GTK_FORM_H__
 #define __GTK_FORM_H__
 
+#ifdef USE_GTK3
+#include <gtk/gtk.h>
+#else
 #include <gdk/gdk.h>
 #include <gtk/gtkcontainer.h>
+#endif
 
 
 #ifdef __cplusplus
@@ -18,10 +22,17 @@
 #endif
 
 #define GTK_TYPE_FORM		       (gtk_form_get_type ())
+#ifdef USE_GTK3
+#define GTK_FORM(obj)		       (G_TYPE_CHECK_INSTANCE_CAST((obj), GTK_TYPE_FORM, GtkForm))
+#define GTK_FORM_CLASS(klass)	       (G_TYPE_CHECK_CLASS_CAST((klass), GTK_TYPE_FORM, GtkFormClass))
+#define GTK_IS_FORM(obj)	       (G_TYPE_CHECK_INSTANCE_TYPE((obj), GTK_TYPE_FORM))
+#define GTK_IS_FORM_CLASS(klass)       (G_TYPE_CHECK_CLASS_TYPE((klass), GTK_TYPE_FORM))
+#else
 #define GTK_FORM(obj)		       (GTK_CHECK_CAST ((obj), GTK_TYPE_FORM, GtkForm))
 #define GTK_FORM_CLASS(klass)	       (GTK_CHECK_CLASS_CAST ((klass), GTK_TYPE_FORM, GtkFormClass))
 #define GTK_IS_FORM(obj)	       (GTK_CHECK_TYPE ((obj), GTK_TYPE_FORM))
 #define GTK_IS_FORM_CLASS(klass)       (GTK_CHECK_CLASS_TYPE ((klass), GTK_TYPE_FORM))
+#endif
 
 
 typedef struct _GtkForm GtkForm;
@@ -33,13 +44,17 @@
 
     GList *children;
 
+#ifndef USE_GTK3
     guint width;
     guint height;
+#endif
 
     GdkWindow *bin_window;
 
+#ifndef USE_GTK3
     GdkVisibilityState visibility;
     gulong configure_serial;
+#endif
 
     gint freeze_count;
 };
@@ -49,7 +64,11 @@
     GtkContainerClass parent_class;
 };
 
+#ifdef USE_GTK3
+GType gtk_form_get_type(void);
+#else
 GtkType gtk_form_get_type(void);
+#endif
 
 GtkWidget *gtk_form_new(void);